1. Field of the Invention
The present invention generally relates to a tool and method for producing semiconductor chips, and more particularly to a wafer frame mounting method for a backside grinding (BSG) tool.
2. Description of the Related Art
Conventional systems utilize semiconductor wafers that are usually thinned by a backside grinding (BSG) process prior to being diced into individual chips for packaging into modules. The final wafer thickness depends on the package design and final module thickness required for a given application. Generally, the conventional grinding processes can produce an 8-inch diameter wafer to a thickness of about 300 .mu.m without major difficulty.
However, thicknesses on the order of about 250 .mu.m or less are difficult (if not impossible) to achieve by the conventional grinding process because the wafer is too fragile to be handled after the grinding operation. Thus, additional costly processing steps, such as etching and/or polishing, are required to strengthen the wafer, or the wafer is likely to be broken or damaged during subsequent handling. This problem will be even more acute as the wafer processing industry migrates to 12-inch wafers.
Additionally, wafers are often warped coming off of the grinder, thereby making difficult the handling and placement of the wafers into cassettes. It is envisioned that future higher density products will have even higher levels of warpage after the grinding operation.